You probably won't get the Range Rover Hybrid in the States. I don't think you even get the diesels. In the UK the V8 supercharged petrol accounts for only 12% of all RR sales.
The hybrid is expected to account for 7% of sales. I got a drive in one this week ahead of UK deliveries in spring 2014.
BTW the quoted 44mpg is UK mpg. Expect 36mpg US.